Lemon balm, scientifically known as Melissa officinalis, is a perennial herb in the mint family. Known for its pleasant scent and calming properties, this herb has recently gained attention as a natural alternative to synthetic insect repellents. The distinctly citrus-scented foliage contains compounds that offer an appealing option for deterring mosquitoes. This article will explore the science behind why this herb works and provide detailed instructions for creating and applying homemade lemon balm repellents.
The Repellent Compounds in Lemon Balm
The effectiveness of lemon balm as a mosquito repellent is directly linked to the volatile oils concentrated within its leaves. The primary compound responsible for the herb’s strong lemon aroma and insect-deterring properties is citronellal. Citronellal, along with monoterpenoids like citronellol and geraniol, creates a scent profile that mosquitoes find highly unappealing. These compounds mask the human scents, such as carbon dioxide and lactic acid, that mosquitoes use to locate their hosts. By overwhelming the insects’ sensitive olfactory receptors, the lemon balm compounds interfere with their ability to track and target a person. Because these oils are volatile and evaporate quickly, frequent reapplication is necessary for any repellent preparation.
Immediate Use Methods
The simplest way to use lemon balm for immediate mosquito protection is by applying fresh leaves directly to your skin. The essential oils are stored in tiny glands on the leaf surface, requiring physical manipulation to break them open. To release the concentrated oil, crush or thoroughly bruise several fresh leaves and stems between your fingers.
Once the leaves release their intense scent, rub the resulting oily residue directly onto exposed skin. Target pulse points and extremities like the wrists, ankles, neck, and behind the ears, as these areas release more heat and human scent. This quick application offers temporary protection for short periods outdoors.
Making Long-Lasting Lemon Balm Repellents
Creating a shelf-stable repellent requires extracting and concentrating the volatile compounds using a solvent like alcohol or oil. These methods yield products with greater potency and a longer shelf life than using fresh leaves alone. The choice of solvent determines the final product, resulting in either a sprayable tincture or a rub-on infused oil.
Alcohol Tincture/Spray
A high-proof alcohol tincture effectively extracts the essential oils and allows for a convenient sprayable application. To begin, loosely fill a clean glass jar about two-thirds full with fresh, slightly crushed lemon balm leaves. Use a neutral spirit, such as vodka or grain alcohol, that is at least 80 proof (40% alcohol), to ensure proper extraction and preservation. Pour the alcohol over the leaves until they are fully submerged.
Seal the jar tightly and place it in a cool, dark location for a minimum of four to six weeks. Gently shaking the jar every day or two helps the extraction process, known as maceration. After the infusion period, strain the liquid through a fine-mesh sieve lined with cheesecloth to remove all solid plant matter. The resulting liquid can then be transferred to a dark glass spray bottle for storage and use.
Oil Infusion
An oil infusion creates a rub-on repellent that is gentler on the skin and is beneficial for those who prefer an alcohol-free application. This method uses a carrier oil like olive, jojoba, or sweet almond oil to draw out the oil-soluble components. For oil infusions, use dried or wilted lemon balm leaves, as fresh leaves contain water that can cause the oil to spoil.
Fill a clean, dry jar approximately halfway with the dried lemon balm, then pour the carrier oil over the herbs, ensuring the plant material is completely submerged. Seal the jar and allow the mixture to infuse for two to six weeks in a warm location, or use a gentle, low-heat method like a double boiler for a faster infusion. Once infused, strain the oil through cheesecloth and store the finished product in a clean, dark glass bottle to protect it from light.
Safe Application and Sourcing
Before applying any concentrated lemon balm preparation, always perform a patch test to check for skin sensitivity or allergic reactions. Apply a small amount of the finished tincture or oil to a discreet area, such as the inner wrist or elbow, and wait 24 hours to observe any redness or irritation. Concentrated herbal preparations can cause reactions in sensitive individuals.
Plant-based repellents require much more frequent reapplication than synthetic counterparts. The volatile oils evaporate quickly, meaning the repellent effect lasts only one to two hours before needing to be refreshed. Reapply the spray or oil every hour, especially during periods of high mosquito activity or after swimming or sweating.
When sourcing the herb, prioritize plants correctly identified as Melissa officinalis and confirm they have been grown without pesticides or chemical treatments. Growing lemon balm yourself is the best way to ensure a clean supply, as it is a resilient and easy-to-cultivate herb. For the highest concentration of compounds, harvest the leaves before the plant flowers, as the essential oil content decreases afterward.